Actually the big bang in itself does not negate there being a God, for what created the big bang? That, they cannot explain, other than it just happened. If the Universe was created from the big bang as theorized, then what existed prior to the big bang, nothing? How can something be created out of nothing unless it was by intelligent design? No, while there may be truth to the big bang it still leaves a lot unanswered. As is so often the case with liberals, atheists just want to accept what they want and refuse to even entertain conflicting arguments that do not adhere to their thinking. They assume they have all the answers, yet they ignore the outstanding questions that remain to which they have no answer.
Absolutely nothing can happen without a force behind it. Nothing.